Surgical repair of damaged soft tissue is a procedure that is being carried out with increasing frequency. The most common method for soft tissue repair is to suture together the torn or damaged portions of the affected tissue. This technique involves the approximation of damaged soft tissue portions or the approximation of damaged soft tissue to a bony insertion site where the suture may be affixed to an anchor.
This relatively simple method carries several drawbacks, however. For instance, healing is dependent on biological interaction and contact that is facilitated by the mechanical fixation. Should complete healing not occur the integrity of the repair becomes solely dependent on the mechanical suture fixation, which can deteriorate over time. Additionally, most failures in soft tissue repair are due at least in part to one or more of poor tissue quality, poor vascular supply and poor tissue contact with the vascular supply, technique variation, and inherent dynamic functional nature of the repair sites. For instance, in rotator cuff repair failure rates are reported to be from 10 to 90%. These failures primarily occur at the interface between the host tissue and the tissue fixation device (typically suture) where the mechanism of failure is primarily suture pull out.
In an attempt to maximize biological contact and increase the likelihood of healing, multiple sutures and sometimes multiple anchors as well, have been arranged at the affected site so as to distribute load evenly across the repair site and maximize contact at the interface of the tissues. However, load distribution is still limited and concentrated at the sutures, and suture can pull through the tissue under heavy or cyclic load. Moreover, such processes require increased knot tying and increased time, which can contribute to the increased possibility of development of complications.
In addition, these repair techniques are strictly mechanical and attempt to merely restore anatomy and mechanical function. As a result, more recent advances have led to the development of tissue augmentation products that can be affixed to the damaged and/or surrounding tissues to facilitate healing, but these are not indicated for primary mechanical repair and aim merely to restore tissue mass at a surgical site. Procedures that require both mechanical fixation and biologic augmentation can be carried out, but these procedures are time consuming in that they require both steps separately, i.e., the mechanical fixation through suturing as well as a separate tissue augmentation process, again leading to increased time for completion and associated increased chance of development of complications
What are needed in the art are implantable materials that can provide improved mechanical repair of soft tissue injuries. What are also needed in the art are materials that can provide for both mechanical repair and tissue augmentation in a single step procedure.